|International Vegetarian Union (IVU)|
Vegetarian Nutrition, Physical Activity and Athletic Performance
by Marcel Hebbelinck, Ph.D., F.A.C.S.M., Professor, Free University of Brussels.
from EVU News, Issue 2 / 1996
Why is the human diet such an active field of inquiry with respect to physical performance? The most obvious reason is that physical activity in general, and athletic performance in particular, is so dependent on the quality and quantity of food intake.
Given the factors of phylogenetic heritage (i.e., apes are vegetarians), the vegetarian diet is most probably the oldest form of nutrition of all early hominids (Gordon 1987). Furthermore, it is a reasonable assumption that seeds, nuts, fruits roots and other plant foods have continued to contribute a major portion of diet of pre-historic people in most tropical and temperate regions.
The spectrum of modern human diets show a remarkable range of ways of feeding, from the high fish and meat diets of the Eskimo to the strict vegetarian diets of some groups of the Indian subcontinent, with every possible combination in-between.
Vegetarian diets themselves clearly can vary greatly and the definition of various types of vegetarian regimens can be distinguished:
Another example is based on observations made in 1970 by Sula Benet, a professor of anthropology, who reported on her visit to Abkhasia: Not long ago, in the village of Tanush in the Soviet Republic of Abkasia, I raised my glass of wine to toast a man who looked no more than 70. May you live as long as Moses (120 years), I said. He was not pleased. He was 119. With regard to health and fitness Dr. Benet observed that they usually are blessed with good eyesight, and most have their own teeth; their posture is unusually erect, even into advanced age; many of the 70 and older take walks of several miles a day swim in mountain streams. Studies led by Soviet and foreign investigators show that, in general signs of arteriosclerosis, when they occurred at all, were found only in extreme old age. There were no reported cases of either mental illness or cancer in a nine-year study of 123 Abkhasians over 100 years old.
Overeating is considered dangerous in Abkhasia, and fat people are regarded as ill. The Abkhasion diet contains very little meat perhaps once or twice a week. At all three meals they eat abista, a corn meal mash cooked in water without salt, which takes the place of bread. Abista is eaten warm with pieces of home-made goat cheese tucked into it. They also consume two glasses of buttermilk a day. The other staples in the Abkhasion daily diet include fresh fruits, especially grapes, fresh vegetables, including onions, tomatoes, cucumbers and cabbage, a wide variety of pickled vegetables, and lima beans, cooked slowly for hours, mashed and served with a sauce of onions, peppers, garlic, pomegranate juice and pepper. Large quantities of garlic are always at hand. They drink neither coffee, nor tea, but they consume in small quantities a locally produced, dry red wine of low alcoholic content. Absent from their diet is sugar, though honey, a local product, is used.
Another anthropologist who describes the values of a frugal diet and an active lifestyle as studied in long lived people of the Caucasus (Abkhasians), the Karakorum Range (Hunzas) and the Andes (Vilkabamba) is Alexander Leaf, a professor of clinical medicine at Harvard Medical School who says in his book entitled Youth in Old Age (Leaf, 1975): Most important, good dietary habits should be established in early life...and endurance exercises are most beneficial... If I can offer you no guaranteed formula of my own of how to obtain a long, vigorous healthy life, let me at least share with you the clue I received from Markhti Targil, age 104, of Duripshi in Abkhasia. Markhti told me that every morning as long as he can remember he walks down the steep hill to bath in the icy waters of a rapid mountain stream. After dressing he climbs back up the hill to his house. Surely any day Markhti can do that he must be too fit to die.
In a survey of the long living Hunza, Pakistani nutritionist Dr. Magsood Ali found that their almost vegetarian diet had a very low caloric intake of 1923 Calories with 50 grams of protein, 36 grams of fat and 354 grams of carbohydrate, meat and dairy products constituting only 1,5 percent of the total (cited in: Leaf, 1975).
Similar figures have been reported by Dr. Guillermo Vela of Quito, who found a striking low caloric consumption also among the elderly of Vilcabamba. The average daily diet provided 1200 calories, with 35 grams of protein, 12 to 19 grams of fat and 200 to 260 grams of carbohydrates. Protein and fat were largely of vegetable origin.
The diet of the Hunzas is mainly grain (wheat, barley and buckwheat), jobs tears and small seeds. Green vegetables (eg spinach and lettuce), root vegetables (eg carrots, turnips, potatoes, radishes) are eaten. Beans, chickpeas and other pulses such as lentils and sprouted pulses are part of their diet: they also eat marrows and pumpkins, as well as plenty of cottage cheese; their fruits are mainly wild apricots and berries, eaten fresh or sun-dried. Meat is eaten only on rare occasions.
Semi or almost vegetarians on a scant diet, all of the above mentioned long lived people (Abkhasians, Hunza and Vilcabamba) share a common feature in their lifestyles, i.e. a great deal of physical activity. The traditional farming and household practices demand heavy work and all are involved from early childhood to terminal days. Superimposed on the physical labour involved in farming is the mountainous terrain. Simply transversing the hills on foot during the days activities sustains a high degree of cardio-vascular fitness as well as muscular strength.
What do we learn from these studies of these three high altitude cultures of long living populations with regard to diet and physical activity? They have in common a frugal semi-vegetarian diet, low in calories, and closely linked to the soil, from which most of the food they eat is taken directly without much refinement, low in fat and proteins mainly from plant origin. Another powerful contributory factor to the health and fitness of these people is undoubtedly the daily habitual physical activity, which consists mainly of walking, hiking, household and farming activities.
Dr. David Davies, a human ecologist at the Gerontological Unit of the University College in London, who has studied the population living in the Vilcabamba region (in the Ecuadorean Andes between 1520 and 1700 metres above sea level), writes that if the centenarians of the Andes had been found twenty years ago, they would by now have been exploited out of existence. For the world was not ready to receive them then, and there was not sufficient interest, as there is today, for their reception into the world of science. The general consciousness and knowledge of people today is such that we now accept vegetarianism at least as a normal possibility for a diet. (Davis, 1975, p.66)
Recent surveys (Slavin, et al,. 1986, Mickenberger, 1989) show, that an increasing number of athletes are adopting vegetarian or semi-vegetarian diets, reducing their intake of meat, and/or increasing their consumption of vegetables, fruits, nuts, seeds and whole grain foods. A remarkable example of an impressive athletic achievement is the so-called Deutschland Lauf (endurance-run through Germany). This long distance run covers 1000 km (about 650 miles) from the Baltic to the Alps and is organized by the department of Sports Medicine and Health Education of the Johannes Gutenberg University in Mainz under the direction of professor Jung. A first pilot study (trial run of 1100km in 19 days) took place in 1981 and was then definitively organised in 1987 with about 150 participants, males and females between 20 and 70 years of age. The participants of this ultralong distance run, taking lacto vegetarian wholefood meals with a lot of fresh fruits and raw vegetables; medical examinations and scientific evaluation showed that this vegetarian diet was adequate in calories, vitamins and minerals. Very often it is said that a vegetarian diet is quite suited for endurance athletes (eg Nyboer, well known Dutch Marathon runner, champion of the seventies), but is less adequate for activities requiring great muscular strength and speed. This belief is contradicted by striking examples of vegetarian top-level performers in athletic events where strength and/or speed is predominant:
Murray Rose was a third generation lacto vegetarian. In an interview, he said that he was raised in a vegetarian family and that he never had eaten meat, fish or any food derived from killed animals. He said, that he was not just abstaining from meat, fish or fowl, but that he believed in a natural wholefood nutrition, such as vegetables, fruit, unrefined rice and wheat products, honey, high quality dairy and soja products, nuts, sesame, millet and sunflower seeds (ref. in Stolzenberg,1974).
In most textbooks on nutrition and athletic performance, general statements are made which can also be observed in a vegetarian diet.
Calories (nowadays expressed in kilojoules; 1 calorie = 4.18 kilojoules). An athlete may require up to more than 6000 calories daily, depending on age, sex, body size, physical condition, type of sport, climate, duration and intensity of the activity.
While a nutritious diet includes sources of carbohydrate, protein and fat (=macronutrients), carbohydrate is considered the best source to meet high energy demands.
CarbohydrateCarbohydrate, in the form of blood glucose, liver and muscle glycogen, provides energy for both short intensive efforts and endurance events. When glycogen is used up, the athlete may become exhausted.
About 55 percent of the total dietary energy should come from carbohydrate.
What carbohydrates should be recommended? Complex carbohydrates have an advantage over simple carbohydrates (= all refined sugars) because they are more nutrient. Nutrient dense foods have a high ratio of vitamins and minerals in relation to energy content. They contain more B-vitamins necessary for metabolism, and more fiber and iron, contribution to a nutritionally balanced diet. High carbohydrate meals help to minimise the depletion of muscle glycogen and subsequent feelings of fatigue that occur after heavy training. Whole grain foods (pastas and cereals) are rich in carbohydrates, but also fresh sweet fruits and sun-dried fruits will provide a healthy source of energy. The latter foodstuffs are to be preferred because they will help to restore the acid/base balance of the blood.
ProteinAbout 10-15 percent of the daily energy content should come from protein food. The R.D.A. (Recommended Daily Allowance) differs in the literature from as low as 0.5g/kg body weight daily to 1g/kg b.w. and well above for athletes engaging in high intensity and long exercise.
Many athletes, especially strength athletes, regularly consume quantities of protein far in excess of the RDA. Apparently they believe this practise is beneficial to their performance, and may increase muscle size and strength. On the contrary, high protein intake beyond caloric requirements will only be stored as fat and excessive amounts may result in ill effects including loss of calcium (hyper calcurial), gout, and dehydration.
Highly active individuals may need more protein than sedentary people, but the safety margin built into the RDA of 0.8g/kg body weight can adequately compensate for the athletes needs, provided he/she follows a balanced diet.
Amino acids are the major constitutuents of proteins. In total, 20 different amino acids can be found in proteins but not every protein contains all 20 and, in addition, the relative proportions of each amino acid may vary widely in different proteins. Of these 20 amino acids, only 11 or perhaps 12 can be produced in the body. The remaining amino acids are called essential or indispensable because they must be obtained via food intake. Plant proteins are mostly not so complete because they lack one or more of the nutritionally essential amino acids. Nevertheless, certain vegetables, such as soy, are quite adequate with regard to essential amino acids. To overcome the limitation in quality of protein it is also recommended to complement certain vegetable proteins with others so as to improve the amino acid profile. Examples of complementary combinations of vegetable proteins are:
FatFats are a concentrated source of energy, but they require more oxygen to metabolise than carbohydrates and are therefore less desirable fuel suppliers for physical performance. Training can increase the bodys ability to use fat for energy. About 30% or less of the daily energy content may come from fat. It should not be forgotten that much of our daily diet contains a variety of fat and that preference should be given to polyunsaturated fats, which are mainly found in non-hydrogenated and non-emulgated plant oils (eg sunflower seed, soy, sesame). In our modern society the RDA of 30% of caloric intake is frequently exceeded and this high fat diet may be associated with increased risk of heart disease.
Vitamins and mineralsVitamins and minerals are important for nutrient and oxidative metabolism and therefore indispensable for athletic performance. A selection from a wide variety of whole food products remains the best advice for obtaining the many different vitamins and minerals needed.
There are some questions about possible marginal iron deficiency impairing athletic performance by reducing the oxygen-carrying capacity of blood and certain metabolic functions related to the production of energy. Iron needs appear to be higher in athletes, especially in female endurance athletes, and therefore need for a supplemental source of iron may be advisable (e.g. green leaf-vegetables, soy beans and soy-derived products, potatoes, dried fruits, pumpkin seeds, whole wheat bread, nuts).
Nutritional supplements and nutrition fadsIn the pursuit of improving athletic ability, many athletes, coaches and trainers often fall prey to nutrition fads. Use of extra vitamins, minerals, amino acids, plant extracts, and other special products available to athletes, has no scientific basis for their efficacy. Energisers, Glycogen replacers, Amino stack, Anabolic revitilisers and others may lure uninformed athletes and coaches to purchase these products, often at outrageous costs. Aronson (1986) has scrutinised some of the most used supplements and found that very few, if any, of these products had a true nutritional value. Furthermore, some athletes take excessive amounts of these products believing that it may thus enhance their performance accordingly, when in fact they may be harmful to both health and performance. The types of supplement and so-called ergogenetic aids for athletes are continually changing. Most often, these products are marketed without any substantiated scientific research indicating the potential benefits or possible harmful side effects.
Large doses of vitamins and minerals in excess of RDA do not improve performance; they even may be harmful. For instance, excess iron intake can decrease zinc absorption (Zinc plays an important role in human growth, it is component of insulin and is involved in many enzymatic processes). Because iron supplementation has been widely advocated as being of potential value to athletes, it is possible that some athletes are oversupplementing themselves with iron and thus compromising their zinc status.
Most of the commercial supplements and so-called ergogenetic aids do not benefit the athlete who keeps to a rational training program and a well balanced diet. A good diet, and a vegetarian regimen may certainly do, can make a difference at the finish line. The basis of a high-performance diet is a variety of healthy natural foods, not supplements.
In conclusion, from the many observations of physically active people of all kinds it is beyond doubt that vegetarian eating styles can adequately meet athletes nutritional needs and can successfully support vigorous training programs.
Prof. Dr.h.c. Marcel Hebbelinck, 10 Merelaan , B-1150 Bruxelles, Tel. +32-267 38 437